Polluted water containing oxidizable contaminants, particularly organic contaminants such as naphthenes, aromatics and oxygenated compounds such as acids, aldehydes, ketones, ethers and the like, can be effectively purified by contacting the polluted water with oxygen and a catalyst consisting essentially of a support, e.g., zinc aluminate promoted with 0.05-20 weight percent of (1) at least two different metals active for initiating oxidative reactions selected from the group consisting of the metals of Groups IIIB, IVB, VB, VIB, VIIB, VIII, IB and VA of the Periodic Table; and (2) a rare earth metal at a temperature in the range of about 350.degree. to 550.degree. F and employing a molar ratio of water to oxygen in the range of 10:1 to 200:1. The organic contaminants are oxidized in this process mostly to carbon oxides and water.
The catalyst mentioned above is known in the art and its preparation and examples for the purification process are described in U.S. Pat. 3,823,088, issued to E. O. Box, Jr., and F. Farha on July 9, 1974.
Although the catalyst described in this patent has quite an extended period of use, the catalyst loses activity during its use in water purification. Therefore, the catalyst has to be replaced and/or regenerated.